File systems for optical discs have made advances through various activities to develop UDF (Universal Disk Format®) specifications published from OSTA (Optical Storage Technology Association).
For write-once discs, the recording method has improved from multi-session recording to file-by-file recording using VAT (Virtual Allocation Table).
On the other hand, for rewritable discs, a volume and file structure has improved from the structure using non-sequential recording defined in ECMA 167, which is the international standard, to the structure using Metadata Partition specified in UDF Revision 2.5 (hereinafter UDF 2.5). Merits to using Metadata Partition include a performance improvement in retrieving metadata, such as file entries/directories, and an increase in the robustness from media damage.
However, Metadata Partition cannot be used for data appending usage on a write-once disc. This is because it is not allowed in UDF 2.5 to use Metadata Partition with VAT, due to the difficulty in implementing this combination.
Typically, it is also difficult to develop a new recording method for a write-once disc. This is because the physical characteristics of the write-once disc do not allow the data which is written at once to be overwritten. As the new recording method needs to be compatible with computer architecture, and needs to be implemented in a drive apparatus, and also considering the resources available of consumer appliances, the study of the new recording method was studied from several aspects.
The present invention has been made in view of the above subjects and includes an objective of providing the merits of Metadata Partition to the data recording usage on a write-once disc.